Description
The pkinit_check_kdc_pkid function in plugins/preauth/pkinit/pkinit_crypto_openssl.c in the PKINIT implementation in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.10.4 and 1.11.x before 1.11.1 does not properly handle errors during extraction of fields from an X.509 certificate, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a malformed KRB5_PADATA_PK_AS_REQ AS-REQ request.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | krb5 | 1.10.1+dfsg-4 | — |
| Debian 13 | krb5 | 1.10.1+dfsg-4 | — |
| Debian 12 | krb5 | 1.10.1+dfsg-4 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | krb5 +6 | 1.10.3-10.el6_4.1 | RHSA-2013:0656 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | krb5 | 1.15-1.1 | openSUSE-SU-2024:10004-1 |
Advisories 2
- RHSA-2013:0656 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- openSUSE-SU-2024:10004-1 krb5-1.15-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- 55040 third-party-advisory
- MDVSA-2013:157 vendor-advisory
- http://web.mit.edu/kerberos/www/krb5-1.10/
- http://krbdev.mit.edu/rt/Ticket/Display.html?id=7570
- http://krbdev.mit.edu/rt/Ticket/Display.html?id=7577
- http://web.mit.edu/kerberos/www/krb5-1.11/
- https://github.com/krb5/krb5/commit/f249555301940c6df3a2cdda13b56b5674eebc2e
- openSUSE-SU-2013:0523 vendor-advisory